CN103278709B - A kind of lightning travelling wave in transmission line characteristic test system - Google Patents

Abstract

A kind of lightning travelling wave in transmission line characteristic test system, is made up of power transmission line lightning shielding electro-magnetic transient die device and intelligent monitoring device; Based on power transmission line and lightning conducter model, shaft tower and tower grounding body Model and insulator model, shaft tower is divided into oblique material section, cross-arm section and main material section, consider insulator and power transmission line and lightning conducter factor simultaneously, build with simulations such as the wave impedance of correspondence, self-impedance, transimpedance, self-admittance, transadmittance and inductance the transient state equivalent electrical circuit that is struck by lightning.By curtage sensor, cascade A/D converter, single-chip microcomputer and display or oscillograph form the latter in turn.Native system diverse location adds dash current, measures the signal of far-end lightning conducter and wire, can analyze the communication process of lightning wave at whole transmission line of electricity, according to analysis result, optimizes the weak section of transmission line of electricity line thunder protection and substation equipment lightning protection.

Description

A kind of lightning travelling wave in transmission line characteristic test system

Technical field

The present invention relates to the electromagnetic transient simulated experiment monitoring system of the power transmission line when being struck by lightning, the electromagnetic transient simulation experiment system particularly when thunder and lightning direct attack shaft tower tower top or a thunderbolt transmission pressure.

Background technology

From various countries' electrical network practical operation situation, thunderbolt remains the main harm of transmission line of electricity safe and reliable operation, and the ratio that the line tripping caused by being struck by lightning accounts for fault sum constantly rises.Power system accident Japanese and that Sweden is over half is all caused because transmission line of electricity is struck by lightning; Egypt also once made the whole nation have a power failure because of thunderbolt power main; The national overall length 3.27 ten thousand kilometers such as USSR (Union of Soviet Socialist Republics), the U.S. that international conference on large HV electric systems is announced, the transmission line of electricity of 275-500kV electric pressure, within continuous 3 years, running, lightening hazard reaches 60% of total accident.Transmission line of electricity is as the part of being the most easily struck by lightning in electrical network, and research power transmission line lightning shielding electromagnetic transient, is of great significance guarantee electric power netting safe running tool.

At present there are no the appearance of transmission line lightning stroke electromagnetic transient simulation experimental monitoring system.

Summary of the invention

The object of this invention is to provide a kind of lightning travelling wave in transmission line characteristic test system (or claiming experiment porch), to input lightning surge electric current at system diverse location, measure the signal of far-end lightning conducter and wire, thus accurate analysis lightning wave is in the communication process of whole transmission line of electricity, and intuitively identify the pattern of transmission line of electricity direct attack or shielding flashover according to measurement gained waveform.

The object of the present invention is achieved like this: a kind of lightning travelling wave in transmission line characteristic test system, is made up of power transmission line lightning shielding electro-magnetic transient die device and intelligent monitoring device;

Above-mentioned power transmission line lightning shielding electro-magnetic transient die device is configured to: shaft tower oblique material section wave impedance Z _t1the other end is connected to shaft tower oblique material section damping resistance R ₁one end and shaft tower oblique material section damping circuit L ₁one end, shaft tower oblique material section damping resistance R ₁the other end and shaft tower oblique material section damping circuit L ₁the other end is connected to cross arm of tower section wave impedance Z simultaneously _t2one end, cross arm of tower section wave impedance Z _t2the other end is connected to cross arm of tower section damping resistance R ₂one end and cross arm of tower section damping circuit L ₂one end, cross arm of tower section damping resistance R ₂the other end and cross arm of tower section damping circuit L ₂the other end is connected in series shaft tower main paragraph wave impedance Z simultaneously _t3after be connected to shaft tower main paragraph damping resistance R ₃one end and shaft tower main paragraph damping circuit L ₃one end, shaft tower main paragraph damping resistance R ₃the other end and shaft tower main paragraph damping circuit L ₃the other end is connected in series grounding body resistance R simultaneously _frear ground connection; Shaft tower oblique material section wave impedance Z _t1one end is connected in series the first current transformer T in turn ₁the first coil, the first lightning conducter self-impedance Z ₁₁, transimpedance Z between the first lightning conducter and the second lightning conducter ₁₂, transimpedance Z between the first lightning conducter with a phase transmission pressure _1a, transimpedance Z between the first lightning conducter with b phase transmission pressure _1band the first transimpedance Z between lightning conducter and c phase transmission pressure _1cafterwards as the first exit, shaft tower oblique material section wave impedance Z _t1one end is connected in series the first current transformer T in turn ₁the second coil, the second lightning conducter self-impedance Z ₂₂and the 3rd current transformer T ₃the second coil after as the second exit, the 3rd current transformer T ₃the first coil and transimpedance Z between the first lightning conducter and the second lightning conducter ₁₂in parallel; First current transformer T ₁tertiary coil and the second current transformer T ₂the first coil all with the minimum value Z of transimpedance between first, second lightning conducter, a phase, b phase, c phase transmission pressure _mminin parallel; Cross arm of tower section wave impedance Z _t2one end is connected in series the first insulator YZ1, the second current transformer T in turn ₂the second coil, a phase transmission pressure self-impedance Z _aaand the 4th current transformer T ₄the second coil after as three terminal, the 4th current transformer T ₄the first coil and transimpedance Z between the first lightning conducter with a phase transmission pressure _1ain parallel; Cross arm of tower section wave impedance Z _t2one end is connected in series the second insulator YZ2 and the second current transformer T in turn ₂tertiary coil after be connected to the self-impedance Z of b phase transmission pressure _bbone end, self-impedance Z _bbother end serial connection the 5th current transformer T ₅the second coil after as the 4th exit, the 5th current transformer T ₅the first coil and transimpedance Z between the first lightning conducter with b phase transmission pressure _1bin parallel; Cross arm of tower section wave impedance Z _t2one end is connected in series the 3rd insulator YZ3 and the second current transformer T in turn ₂the 4th coil after be connected to the self-impedance Z of c phase transmission pressure _ccone end, self-impedance Z _ccother end serial connection the 6th current transformer T ₆the second coil after as the 5th exit, the 6th current transformer T ₆the first coil and transimpedance Z between the first lightning conducter with c phase transmission pressure _1cin parallel; Transadmittance Y between b phase transmission pressure with c phase transmission pressure _bcbe connected to the self-impedance Z of b phase transmission pressure _bbthe self-impedance Z of the other end and c phase transmission pressure _ccbetween the other end; The Y of admittance over the ground of c phase transmission pressure _cobe connected to the self-impedance Z of c phase transmission pressure _ccbetween the other end and ground;

By current sensor and/or voltage sensor, cascade A/D converter, single chip circuit and display or oscillograph form intelligent monitoring device in turn; Current sensor and/or voltage sensor accept the signal from the first ~ five exit of above-mentioned power transmission line lightning shielding electro-magnetic transient die device.

Described A/D converter is 12bit ~ 16bit multi-channel a/d converter.

Also have shock wave current source, shock wave current source is from shaft tower oblique material section wave impedance Z _t1one end is introduced, or from the 3rd insulator YZ3 and the second current transformer T ₂the 4th coil node place introduce.

Described first, second, third insulator adopts the atmospherical discharges gap of analog insulation.

Described first ~ six current transformer T ₁, T ₂, T ₃, T ₄, T ₅, T ₆adopt no-load voltage ratio to be the current transformer of 1:1, the iron core of above-mentioned current transformer all adopts manganese-zinc ferrite.

Described parameter expression as shown in the formula:

$Z_{\mathrm{ii}}=(R_{\mathrm{ii}}+\mathrm{\Δ}{R}_{\mathrm{ii}})+j(2\mathrm{\ω}\×{10}^{-4}\ln \frac{{2h}_i}{{\mathrm{GMR}}_i}+\mathrm{\Δ}{X}_{\mathrm{ii}})$

$Z_{m\min }=\min \left(Z_{\mathrm{ik}}\right)=\min \left(Z_{\mathrm{ki}}\right)=\min [\mathrm{\Δ}{R}_{\mathrm{ik}}+j(2\mathrm{\ω}\×{10}^{-4}\ln \frac{D_{\mathrm{ik}}}{d_{\mathrm{ik}}}+\mathrm{\Δ}{X}_{\mathrm{ik}})]$

$Z_{\mathrm{ik}}=Z_{\mathrm{ki}}=\mathrm{\Δ}{R}_{\mathrm{ik}}+j(2\mathrm{\ω}\×{10}^{-4}\ln \frac{D_{\mathrm{ik}}}{d_{\mathrm{ik}}}+\mathrm{\Δ}{X}_{\mathrm{ik}})-Z_{m\min }$

$Y_{\mathrm{co}}=\mathrm{j\ω}\frac{1}{18\×{10}^6\ln \frac{{2h}_c}{r_c}}$

$Y_{\mathrm{bc}}=\mathrm{j\ω}\frac{1}{18\×{10}^6}\ln \frac{D_{\mathrm{bc}}}{d_{\mathrm{bc}}}$

In formula, j-be imaginary part symbol;

R _ithe radius of-circuit i, i is a, b, c, 1,2;

R _iithe AC resistance of-circuit i, i is a, b, c, 1,2;

H _i-circuit i average suspension height over the ground, i is a, b, c, 1,2;

D _ikdistance between-circuit i and circuit k mirror image, i, k are a, b, c, 1,2, and i ≠ k;

D _ikdistance between-circuit i and circuit k, i, k are a, b, c, 1,2, and i ≠ k;

GMR _ithe geometric mean distance of-circuit i, i is a, b, c, 1,2;

Angular frequency when π f-frequency in ω=2 is f, unit is rad/s;

△ R _ii, △ R _ik, △ X _ii, △ X _ik-the card of taking into account earth effect send correction term, and i, k are a, b, c, and 1,2;

Z _iithe self-impedance of-circuit i, i is a, b, c, 1,2;

Z _mminthe minimum value of-each circuit transimpedance;

Z _ik, Z _kitransimpedance between-circuit i and circuit k and Z _mmindifference, i, k are a, b, c, 1,2;

$Z_{\mathrm{ti}}=60[\ln \frac{2\sqrt{2}{H}_i}{2^{1/8}{\left(r_{\mathrm{ti}}^{1/3}{r}_B^{2/3}\right)}^{1/4}{\left(R_{\mathrm{ti}}^{1/3}{R}_B^{2/3}\right)}^{3/4}}-2]r_{\mathrm{ti}}{R}_{\mathrm{ti}},$ I=1,2 or 3;

$R_i=-2Z_{\mathrm{ti}}[H_i/(H_1+H_2+H_3)\ln \sqrt{\mathrm{\γ}},$ I=1,2 or 3;

L _i=αR _i2H _i/υ _t；

H _ievery section of shaft tower height, i is 1,2,3;

R _tishaft tower main support radius, i is 1,2,3;

R _tishaft tower holder radius, i is 1,2,3;

Z _tievery section of Tower Surge Impedance, i is 1,2,3;

R _b, R _bthe radius of-upper and lower column foot part;

R _ithe damping resistance of every section of shaft tower, i is 1,2,3;

L _ithe damping circuit of every section of shaft tower, i is 1,2,3;

α is ratio of damping;

υ _tfor the light velocity;

γ is attenuation coefficient.

This experimental system has following characteristics and advantage:

1, add dash current at model table diverse location, measure the signal of far-end lightning conducter and wire, the communication process of lightning wave at whole transmission line of electricity can be analyzed, according to analysis result, optimize the weak section of transmission line of electricity line thunder protection and substation equipment lightning protection.Carry out characteristic quantity analysis according to measurement gained waveform, transmission line of electricity can be proposed and attack the mode identification method with shielding flashover directly.

2, dynamic simulation test platform circuit board Parameter adjustable, can obtain effective differentiated lightning protection measure, to diverting type lightning protection device experiment Analysis such as parallel connection gaps on dynamic model experiment platform.

The major influence factors of thunderbolt shaft tower counterattack: lightning conducter is shunted, shaft tower height, pole tower ground resistance, wire operating voltage; The major influence factors of thunderbolt wire: earth-wire protection angle, landform residing for shaft tower circuit, wire operating voltage, shaft tower height.Regulate to change damage to crops caused by thunder influence factor in adjustable extent to model element parameter at dynamic model experiment platform, obtained the optimization model of differentiated lightning protection by adjustment repeatedly.At dynamic model experiment platform, the optimum of the configuration mode of the diverting type lightning protection devices such as parallel connection gaps is studied, reduce tripping rate with lightning strike

Improving Lighting Protection Measures and Insulation Coordination level, is the important guarantee realizing increasing substantially interconnected network operational reliability target.

3, dynamic model experiment platform can provide physical test platform to transmission line of electricity lightning current along the line and lightning surge data acquisition.

The parameter characteristic of thunder and lightning coordinates discussion power system insulation; lightning protection countermeasure, improves lightning protection facility performance, evaluates lightning protection facility to the protection domain of various equipment and transformer station, generating plant and buildings and analyze lightening hazard; distinguish accident responsibility, be all of great significance.Generation current factory and transformer station use oscillograph and lightning arrester mostly for the monitoring of lightning current, but lightning arrester can only record the number of times that thunder and lightning occurs, and can not record the information such as the polarity of lightning current and amplitude, can not provide information accurately for lightning protection; Lightning current occur time amplitude and frequency all higher, oscillograph in transformer station is due to the restriction by self sample frequency, can not accurate recording lightning current waveform, and before lightning current waveform enters transformer station, waveform can distort, therefore measured waveform fict lightning current waveform, accurately can not reflect thunder and lightning actual parameter characteristic.Therefore necessary to the research of lightning parameter.

Due to the randomness of thunder and lightning, actual track is directly tested lightning parameter collection, due to the randomness of thunder and lightning, collection period will be faced long, in every secondary line experiment, all circuit must have a power failure, and the transmission line of electricity that thunder and lightning takes place frequently is in mountain area mostly, repeatedly adjusting monitoring device can be very inconvenient.Tested by the collection at power transmission line lightning shielding electro-magnetic transient dynamic model experiment platform lightning parameter, validity and the stability of lightning monitoring device can be verified, and determine lightning monitoring device installation site and mounting distance.

Accompanying drawing explanation

Fig. 1 is first, second lightning conducter and a phase, b phase, the self-impedance of c phase transmission pressure and the circuit diagram of transimpedance.

Fig. 2 be the first lightning conducter admittance over the ground and with a, b, c phase transmission pressure between the circuit diagram of transadmittance.

The structural drawing of the circuit unit of interval transmission line of electricity (between two shaft towers) model when Fig. 3 is thunder and lightning direct attack tower top.

The structural drawing of the circuit unit of interval model of power transmission system when Fig. 4 is thunderbolt one phase conductor.

Fig. 5 is Tower Surge Impedance simulation block diagram.

Fig. 6, Fig. 7, Fig. 8, Fig. 9 are the corresponding parameter schematic diagram of parallel many conductor systems of simulation shaft tower respectively.

Figure 10 is the illustraton of model of shaft tower and tower grounding body.

Figure 11 is native system hardware block diagram.

Embodiment

A/D converter and processor of single chip computer can adopt HR6100 tester.Tester part of data acquisition adopts parallel acquisition technique, and acquisition rate is up to the every passage of 20Msps.Be particularly suitable for high speed dynamic data Measurement and analysis.The built-in mass storage of HR6100 test macro, containing multiple trigger mode, ensures accurately to catch qualified data, particularly catches the status data that front and back generation occurs dash current.Negative delay length can be arranged, and the longlyest can reach 512K word length.12bit ~ 16bitAD converter is adopted to ensure enough amplitude precisions.Collecting part technical indicator: data acquisition adopts high speed, parallel acquisition, acquisition channel number to be hyperchannel; The most high sampling rate of every passage is 20Msps; Collection has manually and internal trigger mode; The data memory length of every passage is 512k data word.

Movable model experiment table (i.e. experimental system) structure:

1, power transmission line and lightning conducter model;

2, shaft tower and tower grounding body Model;

3, insulator model.

Power transmission line and lightning conducter model:

Circuit π type Equivalent Model selections length of the present invention is L=λ/10, and wherein λ is for acting on circuit frequency spectrum maximum frequency component after Lightning Transient electric current Fourier transform, electromagnetic wavelength in circuit surrounding medium.Therefore, sectionalized line elements relative meets static field hypothesis in lightning wave.

When the invention provides accurate transmission line of lightning strike and shaft tower, the building method of the physical model of lightning channel.Different from traditional model of power transmission system, this model table adds the physical model of ground wire, accurately considers the electromagnetic coupled of ground wire and power transmission line.Self-impedance and the transimpedance (Fig. 1) of ground wire and power transmission line is simulated with multistage equivalent π type equivalent circuit, self-admittance and transadmittance (Fig. 2), directly with the transimpedance of mutual inductor analog line, and on each section of pole tower ground wire, electric current has been installed, voltage monitor, proposes to gather lightning wave data first on ground wire and power transmission line simultaneously.Compared to the lightning wave data only gathered on power transmission line, can binary channels comprehensively analyze can effective exclusive PCR, and have the advantages such as identification intuitively to lightning fault pattern (strikeing back and shielding).

Be each circuit self-impedance in Fig. 1, all the other are transimpedance between circuit.Each circuit end points place's self-admittance in Fig. 2, all the other are the transadmittance between circuit.

Fig. 1 system resulting impedance Z is:

$Z=\left[\begin{array}{ccccc}{Z}_{11}& Z_{12}& Z_{1a}& Z_{1b}& Z_{1c}\\ Z_{21}& Z_{22}& Z_{2a}& Z_{2b}& Z_{2c}\\ Z_{a1}& Z_{a2}& Z_{\mathrm{aa}}& Z_{\mathrm{ab}}& Z_{\mathrm{ac}}\\ Z_{b1}& Z_{b2}& Z_{\mathrm{bs}}& Z_{\mathrm{bb}}& Z_{\mathrm{bc}}\\ Z_{c1}& Z_{c2}& Z_{\mathrm{ca}}& Z_{\mathrm{cb}}& Z_{\mathrm{cc}}\end{array}\right]$

Fig. 2 system shaft tower is to ground wire resultant admittance Y _shunt/ 2 are:

$\frac{Y_{\mathrm{shunt}}}{2}=\left[\begin{array}{ccccc}{Y}_{10}/2& Y_{12}/2& Y_{1a}/2& Y_{1b}/2& Y_{1c}/2\\ Y_{12}/2& Y_{20}/2& Y_{a2}/2& Y_{b2}/2& Y_{c2}/2\\ Y_{1a}/2& Y_{2a}/2& Y_{\mathrm{aa}}/2& Y_{\mathrm{ab}}/2& Y_{\mathrm{ac}}/2\\ Y_{1b}/2& Y_{2b}/2& Y_{\mathrm{ab}}/2& Y_{\mathrm{bb}}/2& Y_{\mathrm{cb}}/2\\ Y_{1c}/2& Y_{2c}/2& Y_{\mathrm{ac}}/2& Y_{\mathrm{bc}}/2& Y_{\mathrm{cc}}/2\end{array}\right]$

Wherein Z ₁₁, Z ₂₂, Z _aa, Z _bb, Z _ccfor each circuit self-impedance, all the other are transimpedance between circuit.Y ₁₀/ 2, Y ₂₀/ 2, Y _ao/ 2, Y _bo/ 2, Y _co/ 2 is each circuit end points place's self-admittance, and all the other are the transadmittance between circuit.

Its component Model as shown in the formula:

$\left[\begin{array}{c}{I}_1\\ I_2\\ I_3\\ I_4\\ I_a\\ I_b\\ I_c\\ I_d\\ I_e\\ I_f\end{array}\right]=\left[\begin{array}{cc}Y+\frac{1}{2}{Y}_{\mathrm{shunt}}& -Y\\ -Y& Y+\frac{1}{2}{Y}_{\mathrm{shunt}}\end{array}\right]\left[\begin{array}{c}{U}_1\\ U_2\\ U_3\\ U_4\\ U_a\\ U_b\\ U_c\\ U_d\\ U_e\\ U_f\end{array}\right]$

Wherein Y=Z ^-1.

In Fig. 3, Fig. 4, T ₁, T ₂, T ₃, T ₄, T ₅, T ₆for no-load voltage ratio is the current transformer of 1:1, wherein T ₁around three windings on iron core, T ₂around upper four windings on iron core.The iron core of current transformer adopts manganese-zinc ferrite, and the maximum useful frequency of manganese-zinc ferrite is 3MHz, R _ffor tower grounding body impulse resistance.

Fig. 3, Fig. 4 illustrate a kind of lightning travelling wave in transmission line characteristic test system, shaft tower oblique material section wave impedance Z _t1the other end is connected to shaft tower oblique material section damping resistance R ₁one end and shaft tower oblique material section damping circuit L ₁one end, shaft tower oblique material section damping resistance R ₁the other end and shaft tower oblique material section damping circuit L ₁the other end is connected to cross arm of tower section wave impedance Z simultaneously _t2one end, cross arm of tower section wave impedance Z _t2the other end is connected to cross arm of tower section damping resistance R ₂one end and cross arm of tower section damping circuit L ₂one end, cross arm of tower section damping resistance R ₂the other end and cross arm of tower section damping circuit L ₂the other end is connected in series shaft tower main paragraph wave impedance Z simultaneously _t3after be connected to shaft tower main paragraph damping resistance R ₃one end and shaft tower main paragraph damping circuit L ₃one end, shaft tower main paragraph damping resistance R ₃the other end and shaft tower main paragraph damping circuit L ₃the other end is connected in series grounding body resistance R simultaneously _frear ground connection; Shaft tower oblique material section wave impedance Z _t1one end is connected in series the first current transformer T in turn ₁the first coil, the first lightning conducter self-impedance Z ₁₁, transimpedance Z between the first lightning conducter and the second lightning conducter ₁₂, transimpedance Z between the first lightning conducter with a phase transmission pressure _1a, transimpedance Z between the first lightning conducter with b phase transmission pressure _1band the first transimpedance Z between lightning conducter and c phase transmission pressure _1cafterwards as the first exit, shaft tower oblique material section wave impedance Z _t1one end is connected in series the first current transformer T in turn ₁the second coil, the second lightning conducter self-impedance Z ₂₂and the 3rd current transformer T ₃the second coil after as the second exit, the 3rd current transformer T ₃the first coil and transimpedance Z between the first lightning conducter and the second lightning conducter ₁₂in parallel; First current transformer T ₁tertiary coil and the second current transformer T ₂the first coil all with the minimum value Z of transimpedance between first, second lightning conducter, a phase, b phase, c phase transmission pressure _mminin parallel; Cross arm of tower section wave impedance Z _t2one end is connected in series the first insulator YZ1, the second current transformer T in turn ₂the second coil, a phase transmission pressure self-impedance Z _aaand the 4th current transformer T ₄the second coil after as three terminal, the 4th current transformer T ₄the first coil and transimpedance Z between the first lightning conducter with a phase transmission pressure _1ain parallel; Cross arm of tower section wave impedance Z _t2one end is connected in series the second insulator YZ2 and the second current transformer T in turn ₂tertiary coil after be connected to the self-impedance Z of b phase transmission pressure _bbone end, self-impedance Z _bbother end serial connection the 5th current transformer T ₅the second coil after as the 4th exit, the 5th current transformer T ₅the first coil and transimpedance Z between the first lightning conducter with b phase transmission pressure _1bin parallel; Cross arm of tower section wave impedance Z _t2one end is connected in series the 3rd insulator YZ3 and the second current transformer T in turn ₂the 4th coil after be connected to the self-impedance Z of c phase transmission pressure _ccone end, self-impedance Z _ccother end serial connection the 6th current transformer T ₆the second coil after as the 5th exit, the 6th current transformer T ₆the first coil and transimpedance Z between the first lightning conducter with c phase transmission pressure _1cin parallel; Transadmittance Y between b phase transmission pressure with c phase transmission pressure _bcbe connected to the self-impedance Z of b phase transmission pressure _bbthe self-impedance Z of the other end and c phase transmission pressure _ccbetween the other end; The Y of admittance over the ground of c phase transmission pressure _cobe connected to the self-impedance Z of c phase transmission pressure _ccbetween the other end and ground.

Also have shock wave current source, shock wave current source is from shaft tower oblique material section wave impedance Z _t1one end is introduced, or from the 3rd insulator YZ3 and the second current transformer T ₂the 4th coil node place introduce.First, second, third insulator adopts the atmospherical discharges gap of analog insulation, or adopts analog equivalent insulator.Parameter expression as shown in the formula:

$Z_{\mathrm{ii}}=(R_{\mathrm{ii}}+\mathrm{\Δ}{R}_{\mathrm{ii}})+j(2\mathrm{\ω}\×{10}^{-4}\ln \frac{2h_i}{{\mathrm{GMR}}_i}+\mathrm{\Δ}{X}_{\mathrm{ii}})$

$Z_{m\min }=\min \left(Z_{\mathrm{ik}}\right)=\min \left(Z_{\mathrm{ki}}\right)=\min [\mathrm{\Δ}{R}_{\mathrm{ik}}+j(2\mathrm{\ω}\×{10}^{-4}\ln \frac{D_{\mathrm{ik}}}{d_{\mathrm{ik}}}+\mathrm{\Δ}{X}_{\mathrm{ik}})]$

$Z_{\mathrm{ik}}=Z_{\mathrm{ki}}=\mathrm{\Δ}R+j(2\mathrm{\ω}\×{10}^{-4}\ln \frac{D_{\mathrm{ik}}}{d_{\mathrm{ik}}}+\mathrm{\Δ}{X}_{\mathrm{ik}})-Z_{m\min }$

$Y_{\mathrm{co}}=\mathrm{j\ω}\frac{1}{18\×{10}^6\ln \frac{{2h}_c}{r_c}},$ Usually, $Y_{\mathrm{io}}=\mathrm{j\ω}\frac{1}{18\×{10}^6\ln \frac{{2h}_i}{r_i}}$ (i is a, b, c, 1,2)

$Y_{\mathrm{bc}}=\mathrm{j\ω}\frac{1}{18\×{10}^6}\ln \frac{D_{\mathrm{bc}}}{d_{\mathrm{bc}}},$ Usually, $Y_{\mathrm{ik}}=\mathrm{j\ω}\frac{1}{18\×{10}^6}\ln \frac{D_{\mathrm{ik}}}{d_{\mathrm{ik}}}$ (i is a, b, c, 1,2)

In formula, r _ithe radius of-circuit i, i is a, b, c, 1,2;

R _iithe AC resistance of-circuit i, i is a, b, c, 1,2;

H _i-circuit i average suspension height over the ground, i is a, b, c, 1,2;

D _ikdistance between-circuit i and circuit k mirror image, i, k are a, b, c, 1,2, and i ≠ k;

D _ikdistance between-circuit i and circuit k, i, k are a, b, c, 1,2, and i ≠ k;

GMR _ithe geometric mean distance of-circuit i, i is a, b, c, 1,2;

Angular frequency when π f-frequency in ω=2 is f, unit is rad/s;

△ R _ii, △ R _ik, △ X _ii, △ X _ik-the card of taking into account earth effect send correction term, and i, k are a, b, c, and 1,2;

Z _iithe self-impedance of-circuit i, i is a, b, c, 1,2;

Z _mminthe minimum value of-each circuit transimpedance;

Z _ik, Z _kitransimpedance between-circuit i and circuit k and Z _mmindifference, i, k are a, b, c, 1,2;

$Z_{\mathrm{ti}}=60[\ln \frac{2\sqrt{2}{H}_i}{2^{1/8}{\left(r_{\mathrm{ti}}^{1/3}{r}_B^{2/3}\right)}^{1/4}{\left(R_{\mathrm{ti}}^{1/3}{R}_B^{2/3}\right)}^{3/4}}-2]r_{\mathrm{ti}}{R}_{\mathrm{ti}},$ I=1,2 or 3;

$R_i=-2Z_{\mathrm{ti}}[H_i/(H_1+H_2+H_3)]\ln \sqrt{\mathrm{\γ}},$ I=1,2 or 3;

L _i=αR _i2H _i/υ _t；

H _ievery section of shaft tower height, i is 1,2,3;

R _tishaft tower main support radius, i is 1,2,3;

R _tishaft tower holder radius, i is 1,2,3;

Z _tievery section of Tower Surge Impedance, i is 1,2,3;

R _b, R _bthe radius of-upper and lower column foot part;

R _ithe damping resistance of every section of shaft tower, i is 1,2,3;

L _ithe damping circuit of every section of shaft tower, i is 1,2,3;

α is ratio of damping;

υ _tfor the light velocity;

γ is attenuation coefficient.

Shown in Fig. 3, Fig. 4, this circuit model is not started with from circuit positive sequence, negative phase-sequence, zero sequence impedance, but simulate the mutual inductance between each circuit respectively by actual conditions, when mutual inductance between each circuit is completely by simulation, its external characteristic (positive sequence, negative phase-sequence and zero sequence impedance) is also just consistent with actual track.Model can simulate each alternate mutual inductance completely, can reflect the electric parameters feature of transmission line of electricity all sidedly, and the inductance parameters of wire and lightning conducter adopts impedor to simulate, and the realization of model and parameter adjustment are conveniently.

By installing lighting current sensor at pole tower ground wire support and insulator chain branch road.Can distinguish the lightning strike spot of circuit, when circuit generation shielding accident, the amplitude of lightning current that the sensor of corresponding insulator chain branch road measures is more much bigger than the signal of pole tower ground wire support upper sensor record; When there is counterattack accident, except insulator chain flashover has signal record mutually, pole tower ground wire holder sensor also has corresponding wave recording.

By the monitoring to ground wire along the line and electric power line pole tower position voltage waveform, when generation lightning strike accident, the lightning surge waveform monitored can be utilized, utilize positioning using TDOA and lightning channel attenuation characteristic is counter pushes away, determine accident point lightning surge waveform.

Shaft tower and tower grounding body Model (see Fig. 5 Figure 10):

Super UHV transmission line shaft tower height is higher, and shaft tower everywhere width all has larger difference, has larger impact for the propagation of lightning current on tower body, to the accurate simulation of lightning current communication process on shaft tower, depends on the precision of Tower Surge Impedance simulation.

Lumped inductance in regular method and single wave impedance are not suitable for highly higher, baroque shaft tower.

Adopt multi-wave impedance model under parallel many conductor systems (see Fig. 6 ~ Fig. 9) and not parallel many conductor systems, can the communication process of lightning current on accurate simulation shaft tower.

In lightning protection calculation, the ratio of the current potential that under lightning surge effect, tower top presents and the dash current that tower top injects, i.e. the shock response wave impedance of shaft tower, it directly has influence on the result of calculation of tower top current potential.The lumped inductance that the lightning protection calculation method of China's current design criteria adopts carrys out analog line shaft tower, just have ignored the impact of shaft tower ground capacitance, and the resultant error drawn thus is comparatively large, and when calculating, the impulse earthed resistance impact of shaft tower is exaggerated, and precision is not high.In fact, when lightning wave is propagated along shaft tower, the inductance of the unit length of differing heights shaft tower part is not identical with electric capacity, this is change with regard to making the wave impedance along shaft tower distribution, in the engineering calculation of reality, adopt multi-wave impedance model during the calculating of shaft tower, simulation of being merotomized by shaft tower, result of calculation is more realistic than lumped inductance.

According to diffusing effect and the kelvin effect of tower grounding body, in analysis impact diffusing process, soil parameters time-varying characteristics are with space electric field changes in distribution rule;

The impact impedance of tower grounding body, by the amplitude and the frequency influence that flow through dash current, shows stronger nonlinear characteristic.

$I_g=\frac{E_0\mathrm{\ρ}}{2\mathrm{\π}{R}_0^2}$ $R_T=\frac{R_0}{\sqrt{1+I/I_g}}.$

Insulator model:

The insulator model of Novel lightning-proof parallel connection gaps---there is the parallel connection gaps of arc extinguishing ability

By regulating insulator chain length, the size of parallel connection gaps and the structure of arc-control device, change flashover voltage, and probability of sustained arc, analyze and research to tripping rate with lightning strike, the insulator characteristic on Reality simulation circuit, obtains the configuration mode of the diverting type lightning protection devices such as parallel connection gaps.

Claims (5)

1. a lightning travelling wave in transmission line characteristic test system, is characterized in that, is made up of power transmission line lightning shielding electro-magnetic transient die device and intelligent monitoring device;

Above-mentioned power transmission line lightning shielding electro-magnetic transient die device is configured to: shaft tower oblique material section wave impedance Z _t1one end is connected to shaft tower oblique material section damping resistance R ₁one end and shaft tower oblique material section damping circuit L ₁one end, shaft tower oblique material section damping resistance R ₁the other end and shaft tower oblique material section damping circuit L ₁the other end is connected to cross arm of tower section wave impedance Z simultaneously _t2one end, cross arm of tower section wave impedance Z _t2the other end is connected to cross arm of tower section damping resistance R ₂one end and cross arm of tower section damping circuit L ₂one end, cross arm of tower section damping resistance R ₂the other end and cross arm of tower section damping circuit L ₂the other end is connected in series shaft tower main paragraph wave impedance Z simultaneously _t3after be connected to shaft tower main paragraph damping resistance R ₃one end and shaft tower main paragraph damping circuit L ₃one end, shaft tower main paragraph damping resistance R ₃the other end and shaft tower main paragraph damping circuit L ₃the other end is connected in series grounding body resistance R simultaneously _frear ground connection; Shaft tower oblique material section wave impedance Z _t1the other end is connected in series the first current transformer T in turn ₁the first coil, the first lightning conducter self-impedance Z ₁₁, transimpedance Z between the first lightning conducter and the second lightning conducter ₁₂, transimpedance Z between the first lightning conducter with a phase transmission pressure _1a, transimpedance Z between the first lightning conducter with b phase transmission pressure _1band the first transimpedance Z between lightning conducter and c phase transmission pressure _1cafterwards as the first exit, shaft tower oblique material section wave impedance Z _t1the other end is connected in series the first current transformer T in turn ₁the second coil, the second lightning conducter self-impedance Z ₂₂and the 3rd current transformer T ₃the second coil after as the second exit, the 3rd current transformer T ₃the first coil and transimpedance Z between the first lightning conducter and the second lightning conducter ₁₂in parallel; First current transformer T ₁tertiary coil and the second current transformer T ₂the first coil all with the minimum value Z of transimpedance between first, second lightning conducter, a phase, b phase, c phase transmission pressure _mminin parallel; Cross arm of tower section wave impedance Z _t2one end is connected in series the first insulator YZ1, the second current transformer T in turn ₂the second coil, a phase transmission pressure self-impedance Z _aaand the 4th current transformer T ₄the second coil after as three terminal, the 4th current transformer T ₄the first coil and transimpedance Z between the first lightning conducter with a phase transmission pressure _1ain parallel; Cross arm of tower section wave impedance Z _t2one end is connected in series the second insulator YZ2 and the second current transformer T in turn ₂tertiary coil after be connected to the self-impedance Z of b phase transmission pressure _bbone end, self-impedance Z _bbother end serial connection the 5th current transformer T ₅the second coil after as the 4th exit, the 5th current transformer T ₅the first coil and transimpedance Z between the first lightning conducter with b phase transmission pressure _1bin parallel; Cross arm of tower section wave impedance Z _t2one end is connected in series the 3rd insulator YZ3 and the second current transformer T in turn ₂the 4th coil after be connected to the self-impedance Z of c phase transmission pressure _ccone end, self-impedance Z _ccother end serial connection the 6th current transformer T ₆the second coil after as the 5th exit, the 6th current transformer T ₆the first coil and transimpedance Z between the first lightning conducter with c phase transmission pressure _1cin parallel; Transadmittance Y between b phase transmission pressure with c phase transmission pressure _bcbe connected to the self-impedance Z of b phase transmission pressure _bbthe self-impedance Z of the other end and c phase transmission pressure _ccbetween the other end; The Y of admittance over the ground of c phase transmission pressure _cobe connected to the self-impedance Z of c phase transmission pressure _ccbetween the other end and ground;

By current sensor and/or voltage sensor, cascade A/D converter, single chip circuit and display or oscillograph form intelligent monitoring device in turn; Current sensor and/or voltage sensor accept the signal from the first ~ five exit of above-mentioned power transmission line lightning shielding electro-magnetic transient die device.

2. a kind of lightning travelling wave in transmission line characteristic test system according to claim 1, is characterized in that, described A/D converter is 12bit ~ 16bit multi-channel a/d converter.

3. a kind of lightning travelling wave in transmission line characteristic test system according to claim 1, is characterized in that also having shock wave current source, and shock wave current source is from shaft tower oblique material section wave impedance Z _t1the other end is introduced, or from the 3rd insulator YZ3 and the second current transformer T ₂the 4th coil node place introduce.

4. a kind of lightning travelling wave in transmission line characteristic test system according to claim 3, is characterized in that, described first, second, third insulator adopts the atmospherical discharges gap of analog insulation.

5. a kind of lightning travelling wave in transmission line characteristic test system according to claim 4, is characterized in that, described first ~ six current transformer T ₁, T ₂, T ₃, T ₄, T ₅, T ₆adopt no-load voltage ratio to be the current transformer of 1:1, the iron core of above-mentioned current transformer all adopts manganese-zinc ferrite.